WO2019207806A1 - Refrigerant distributor, heat exchanger, and air conditioner - Google Patents

Abstract

A refrigerant distributor that is connected to the respective end portions of a plurality of flat heat transfer tubes (1) forming a refrigerant flow path, and that connects the plurality of flat heat transfer tubes (1), thereby distributing a refrigerant. The refrigerant distributor (3x) is equipped with a flat-tube-side header member (31x) and a combined header member (34x) which are combined with each other. The flat-tube-side header member (31x) and the combined header member (34x) are combined to form a narrow flow path (38).

Description

Refrigerant distributor, heat exchanger and air conditioner

The present invention relates to a refrigerant distributor (header) capable of optimizing the distribution amount of gas-liquid two-phase refrigerant to be flowed to each of a plurality of heat transfer tubes, a heat exchanger including the refrigerant distributor, and an air conditioner. .

Many air conditioners that support air conditioning are currently using cross fin tube heat exchangers composed of circular copper heat transfer tubes and aluminum strip fins. This heat exchanger performs heat exchange between the refrigerant and air by flowing a fluorocarbon refrigerant in the copper heat transfer tube.

On the other hand, parallel flow type heat exchangers are widely used in automobile radiators and air conditioners for cooling to reduce size, weight, performance, and cost. In this heat exchanger, two header pipes are provided at both end openings of a plurality of flat heat transfer tubes brazed with aluminum fins on the outer surface, and the inflow side header pipe is connected to the outflow side via each flat heat transfer tube. It is a heat exchanger of the form which makes a refrigerant flow toward a header pipe.

In a parallel flow type heat exchanger, in order to make all the fin areas work effectively, it is necessary to flow an appropriate amount of liquid refrigerant to each of a plurality of flat heat transfer tubes arranged vertically.

However, in the heat exchanger, the refrigerant flows as a refrigerant in a gas-liquid two-phase state while changing the phase of evaporation and condensation, so that it stands in the vertical direction under the condition that the flow rate of the refrigerant is small and the momentum is low. Since the liquid refrigerant in the header pipe on the inflow side stays downward due to the influence of gravity, there is a tendency that it is difficult to supply sufficient liquid refrigerant to the flat heat transfer pipe connected to the upper part of the header pipe on the inflow side.

As a result, when the parallel flow heat exchanger is used as an evaporator, the amount of liquid refrigerant to be supplied is reduced in the upper one of the stacked flat heat transfer tubes, and all of the liquid refrigerant is upstream of the flat heat transfer tubes. Since it evaporates, heat absorption due to the evaporation of the liquid refrigerant does not occur downstream from the middle stream. That is, in the upper flat heat transfer tube, there is a problem that the liquid component of the refrigerant is small and the degree of superheat increases from the middle flow to the downstream, and the heat transfer area in that portion is not effectively used.

On the other hand, in the laminated flat heat transfer tubes below, the amount of liquid refrigerant supplied is excessive, so that the liquid refrigerant remains even at the outlet of the flat heat transfer tubes. That is, from the flat heat transfer tube below, the liquid refrigerant that has left the heat absorption capacity flows out, which causes a problem that the efficiency of the entire heat exchanger is deteriorated.

In addition, if a “liquid return” occurs in which the liquid refrigerant flows from the lower flat heat transfer tube into the compressor downstream of the heat exchanger, the liquid refrigerant may damage the compression chamber of the compressor. In order to avoid this, it is necessary to evaporate the liquid refrigerant completely by the expansion valve upstream of the heat exchanger and reducing the evaporation pressure to reach the outlet of the heat exchanger. There is a problem that the energy consumption in the vessel is increased.

In order to avoid such problems, when using a parallel flow type heat exchanger as an evaporator, the liquid refrigerant in each flat heat transfer tube is completely eliminated at a substantially aligned position near the header tube on the outflow side. Desirable to maximize heat exchanger performance. In particular, when supplying air at a constant wind speed to a heat exchanger, such as an outdoor unit of an air conditioner, it is required that the refrigerant can be equally distributed to each flat heat transfer tube without drift.
As a conventional technique for solving such a problem, for example, there is one shown in FIG. In this example, in order to improve refrigerant distribution in a vertically standing header, a part of the internal space of the header is partitioned by a partition, and a plurality of through holes are provided in the partition. As a result, the refrigerant is to be uniformly distributed to the flat heat transfer tubes.

In addition, Patent Document 2 and Patent Document 3 have a header structure that is divided in the longitudinal direction for ease of manufacturing itself and ease of making an internal structure for refrigerant distribution, regardless of the distribution structure. It is shown.

Japanese Patent No. 5775226 JP 2009-270781 A Japanese Patent No. 4405819

In Patent Document 1, the refrigerant discharged from the sectioned space in the header has a flow passage cross-sectional area that increases, so the flow rate of the liquid refrigerant is reduced, and the liquid refrigerant is easily subjected to the action of gravity. Easy to fall. In particular, the liquid refrigerant tends to stay in the lower part due to the influence of gravity in the low refrigerant flow rate region. In such a case, the liquid may flow unevenly in the lower heat transfer tube.

In Patent Document 2, a folded flow path or a branch flow path is configured by a divided header structure. As the refrigerant flow path, the refrigerant flows one flat heat transfer tube at a time, and the refrigerant does not flow through the plurality of heat transfer tubes. When the amount of circulation is large, the cross-sectional area of the flow path is insufficient, so that the pressure loss becomes large and the saturation temperature is lowered downstream in the flow direction.

In Patent Document 3, in the divided header structure, the refrigerant flow path cannot be narrowed, and the liquid refrigerant accumulates below due to the action of gravity, and the problem of refrigerant distribution when the heat exchanger is used as an evaporator. was there.

The present invention is an invention for solving the above-described problems, and is capable of supplying liquid refrigerant to each flat heat transfer tube in a parallel flow evaporator even when operating under minimum load conditions or intermediate load conditions. An object of the present invention is to provide a refrigerant distributor capable of suppressing the unevenness of the quantity with a simple structure and improving the performance as an evaporator, a heat exchanger including the refrigerant distributor, and an air conditioner.

In order to achieve the above object, the refrigerant distributor of the present invention is a refrigerant distributor that is connected to the end portions of a plurality of heat transfer tubes forming a refrigerant flow path, communicates the plurality of heat transfer tubes, and distributes the refrigerant. The refrigerant distributor includes a first member and a second member to be combined with each other, and the narrow channel is formed by combining the first member and the second member.

The first member and the second member are formed of a plate material, and the first member and the second member have a D-shaped cross section formed by bending the plate material, and are spaced apart from a part of the D-shaped linear portion. And the first member and the second member are combined through the separated portion, and a narrow channel is formed between the D-shaped straight portions of the first member and the second member facing each other. And The first member has a concave cross section, and the second member is fitted to the inner surface of the first member to form a narrow channel. Other aspects of the present invention will be described in the embodiments described later.

According to the present invention, even during operation under a minimum load condition or an intermediate load condition, the bias of the liquid refrigerant supply amount to each flat heat transfer tube in the parallel flow type evaporator is suppressed with a simple structure, The performance as an evaporator can be improved.

It is a figure which shows the external appearance structure of the heat exchanger which concerns on 1st Embodiment. It is a figure which shows the structure of the heat exchanger at the time of using the flat heat exchanger tube which concerns on 1st Embodiment. It is a figure which shows the structure of the flat heat exchanger tube which concerns on 1st Embodiment. It is a figure which shows the structure of the header of the heat exchanger which concerns on 1st Embodiment. It is a figure which shows the cross section of the header of the heat exchanger which concerns on 1st Embodiment. It is a figure which shows that the header which concerns on 1st Embodiment is point symmetrical. It is a figure which shows the decomposition | disassembly state of the header of the heat exchanger which concerns on 1st Embodiment. It is a figure which shows the longitudinal cross-section of the header of the heat exchanger which concerns on 1st Embodiment. It is a figure which shows the brazing surface of the refrigerant distributor which concerns on 1st Embodiment. It is a figure which shows the other brazing surface of the refrigerant distributor which concerns on 1st Embodiment. It is a figure which shows the external appearance structure of the heat exchanger which concerns on 2nd Embodiment. It is a figure which shows the cross section of the header of Example 1 which concerns on 2nd Embodiment. It is a figure which shows the side surface of the header of the heat exchanger of Example 1 which concerns on 2nd Embodiment. It is a figure which shows the cross section of the header of the heat exchanger of Example 2 which concerns on 2nd Embodiment, and a header insertion member is a figure of a concave shape member. It is a figure which shows the cross section of the header of the heat exchanger of Example 2 which concerns on 2nd Embodiment, and a header insertion member is a figure of a cylinder shape (hollow shape). It is a figure which shows the cross section of the header of the heat exchanger of Example 2 which concerns on 2nd Embodiment, and a header insertion member is a figure of H shape. It is a figure which shows the cross section of the header of the heat exchanger of Example 2 which concerns on 2nd Embodiment, and a header insertion member is a figure of trapezoid shape. It is a figure which shows the cross section of the header of the heat exchanger of Example 3 which concerns on 2nd Embodiment. It is a figure which shows the cross section of the header of the heat exchanger of Example 4 which concerns on 2nd Embodiment. It is a figure which shows the cross section of the header of the heat exchanger of Example 5 which concerns on 2nd Embodiment, and is a figure used as a reference | standard. It is a figure which shows the cross section of the header of the heat exchanger of Example 5 which concerns on 2nd Embodiment, and is a figure which sets the insertion length of a header insertion member long. It is a figure which shows the cross section of the header of the heat exchanger of Example 5 which concerns on 2nd Embodiment, and is a figure which inserts a member different from a header insertion member in a flow path. It is a figure which shows the attachment method of the perforated partition plate in the header of Example 6 which concerns on 2nd Embodiment. It is a figure which shows the other example of the attachment method of the perforated partition plate in the header of Example 6 which concerns on 2nd Embodiment. It is a figure which shows the other example of the attachment method of the perforated partition plate in the header of Example 6 which concerns on 2nd Embodiment. It is a figure which shows the structure of the perforated partition plate of the header of Example 7 which concerns on 2nd Embodiment. It is a figure which shows the other structure of the perforated partition plate of the header of Example 7 which concerns on 2nd Embodiment. It is a figure which shows the perforated board for the drift prevention in the header of Example 8 which concerns on 2nd Embodiment. It is a figure which shows the longitudinal cross-section of the perforated board for drift prevention in the header of Example 8 which concerns on 2nd Embodiment. It is a figure which shows the position of the partition plate of the header insertion member of Example 9 which concerns on 2nd Embodiment. It is a figure explaining a refrigerating cycle. It is a figure explaining the superheat degree by the drift of the refrigerant | coolant distribution of a heat exchanger, and is a figure when there is no drift of a liquid refrigerant. It is a figure explaining the superheat degree by the drift of the refrigerant | coolant distribution of a heat exchanger, and is a figure in case there exists a drift of a liquid refrigerant. It is a schematic diagram of the header structure as a comparative example, and is a figure which shows a round cross section. It is a schematic diagram of the header structure as a comparative example, and is a figure which shows the cross section of the header comprised with two members. It is a schematic diagram of the header structure as a comparative example, and is a figure which shows the other cross section of the header comprised with two members.

DESCRIPTION OF EMBODIMENTS Embodiments for carrying out the present invention will be described in detail with reference to the drawings as appropriate.
First, a refrigeration cycle to which the refrigerant distributor and the heat exchanger of the present embodiment are applied will be described first, and conventional problems will be described in detail.

FIG. 21 is a diagram for explaining the refrigeration cycle. Here, the refrigeration cycle of the heat pump type air conditioner AC will be described with reference to FIG. 21, taking the heating operation as an example. As shown here, the air conditioner AC includes a compressor 8, a four-way valve 9, an indoor heat exchanger 101, an expansion valve 103, an outdoor heat exchanger 106, and the like.

The compressor 8 compresses the gas refrigerant, and the refrigerant 60 that has been brought to a high temperature / high pressure state by the compressor 8 is led to the indoor heat exchanger 101 (condenser) in the indoor unit 100 via the four-way valve 9. It is burned. And the room | chamber interior is warmed because the high temperature refrigerant | coolant which flows through the inside of the flat heat exchanger tube of the indoor heat exchanger 101 dissipates to the indoor air supplied from the air blower 102. At this time, in the flat heat transfer tube, the gas refrigerant that has been deprived of heat gradually liquefies, and from the outlet of the indoor heat exchanger 101, the supercooled liquid refrigerant that is several degrees C lower than the saturation temperature flows out.

Thereafter, the liquid refrigerant that has flowed out of the indoor unit 100 becomes a gas-liquid two-phase refrigerant in a low-temperature and low-pressure state by an expansion action when passing through the expansion valve 103. This low-temperature, low-pressure gas-liquid two-phase refrigerant is guided to the outdoor heat exchanger 106 (evaporator) in the outdoor unit 105. And the low-temperature refrigerant | coolant which flows through the inside of the flat heat exchanger tube of the outdoor heat exchanger 106 absorbs heat from the external air supplied from the air blower 107, so that the dryness of the refrigerant (= mass velocity of gas / (mass velocity of liquid + gas) Mass velocity))). At the outlet of the outdoor heat exchanger 106, the refrigerant is gasified and returned to the compressor 8 with a degree of superheat of several degrees Celsius. The heating operation of the air conditioner AC is realized by the series of refrigeration cycles in which the refrigerant 60 circulates counterclockwise as described above.

On the other hand, during the cooling operation, the four-way valve 9 is switched to form a refrigeration cycle in which the refrigerant 61 circulates clockwise. In this case, the indoor heat exchanger 101 acts as an evaporator, and the outdoor heat exchanger 106 acts as a condenser.

Next, when the indoor heat exchanger 101 or the outdoor heat exchanger 106 acts as an evaporator, the state of refrigerant drift that occurs in the evaporator will be described with reference to FIGS. 22A and 22B. 22A and 22B are schematic and schematic views of the evaporator, and a part of the evaporator is simplified, such as omitting the individual display of the flat heat transfer tube.

FIG. 22A is a diagram for explaining the degree of superheat due to the drift of refrigerant distribution in the heat exchanger, and is a diagram when there is no drift of liquid refrigerant. FIG. 22B is a diagram for explaining the degree of superheat due to the drift of refrigerant distribution in the heat exchanger, and is a diagram when there is a drift of liquid refrigerant. As shown in these figures, the heat exchanger is provided with headers 3a and 3b that are substantially perpendicular to the left and right, and connected by a number of flat heat transfer tubes 1 that are stacked in the vertical direction therebetween. Each flat heat transfer tube 1 is brazed with a fin for enlarging the heat transfer area, but is not shown here. Further, in the flat heat transfer tube 1, the hatched portion is a two-phase region 90 through which the gas-liquid two-phase refrigerant flows, and the white portion is an overheat region 91 through which the gas refrigerant flows.

22A and 22B, in the parallel flow type evaporator, low-temperature and low-pressure gas-liquid two-phase refrigerant flows from the lower part of the header 3b. The refrigerant flowing in flows in the flat heat transfer tubes 1 in the order of the regions (A) → (B) → (C) → (D) while changing the flow direction, and exchanges heat with the air passing between the flat heat transfer tubes 1 ( After the heat absorption), the refrigerant is discharged from the upper portion of the header 3b as a medium temperature / low pressure refrigerant.

As shown in FIG. 22A, when the refrigerant knitting flow does not occur, that is, when the flow velocity of the refrigerant is large and a substantially equal amount of gas-liquid two-phase refrigerant is supplied to each flat heat transfer tube 1 in the region (D), At any height, the flat heat transfer tube 1 becomes the superheated region 91 from the two-phase region 90 at the same distance from the inflow side, so only the gas refrigerant that has sufficiently absorbed heat flows out of any flat heat transfer tube 1. Yes.

On the other hand, as shown in FIG. 22B, when a drift of the liquid refrigerant occurs, that is, gravity acts on the gas-liquid two-phase refrigerant having a low flow velocity in the header 3a and flows into the flat heat transfer tube 1 above the region (D). When the amount of liquid refrigerant is small and the amount of liquid refrigerant flowing into the lower flat heat transfer tube 1 increases, the two-phase region 90 is below and the superheat region 91 is above in the vicinity of the outlet of the region (D).

As described above, when the gas-liquid two-phase refrigerant containing a large amount of liquid refrigerant returns to the compressor 8, the “liquid return” causes damage to the compression chamber. In order to avoid this, it is necessary to throttle the expansion valve 103 upstream of the evaporator to lower the evaporation pressure (temperature) so that the liquid refrigerant is completely gasified in the vicinity of the outlet of the region (D) in FIG. 22B. There is. However, when the evaporation pressure is lowered, there is a problem that the compression work increases and the energy saving performance of the air conditioner is hindered.

Further, when refrigerant drift occurs, the two-phase region 90 is short and the superheat region 91 is long in the flat heat transfer tube 1 above the region (D), so that the two-phase region 90 greatly contributes to the heat absorption from the air. There is a problem that the heat transfer area decreases and the compression work increases.
In order to solve the above problems, various methods of Patent Documents 1 to 3 have been tried.

FIG. 23A is a schematic diagram of a header structure as a comparative example, and shows a round cross section. FIG. 23B is a schematic diagram of a header structure as a comparative example, and is a diagram showing a cross-section of a header constituted by two members. FIG. 23C is a schematic diagram of a header structure as a comparative example, and is a diagram showing another cross-section of the header configured by two members.

FIG. 23A is a header showing a round cross section that is frequently used mainly for condensers such as radiators for automobiles. The header 3a to which the flat heat transfer tube 1 is connected has a round shape. FIG. 23B shows the structure of the header divided in Patent Document 3. The header 3a includes a first member 310a and a second member 340a. In addition, there is a divided header structure as shown in FIG. 23C. The header 3a includes a first member 311a and a second member 341a.

In the header structures of FIGS. 23A, 23B, and 23C, since the cross-sectional area of the flow path is large, the speed of the liquid refrigerant tends to be small, and it tends to accumulate at the lower part in the header.

For this reason, in this embodiment, even during operation under the minimum load condition or intermediate load condition, the bias of the liquid refrigerant supply amount to each flat heat transfer tube in the parallel flow evaporator is suppressed with a simple structure. And the refrigerant distributor (header) which can improve the performance as an evaporator is proposed.

<< first embodiment >>
FIG. 1 is a diagram illustrating an external configuration of a heat exchanger according to the first embodiment. FIG. 2 is a diagram illustrating a state before the headers 3x and 3y are inserted into the flat heat transfer tube 1 according to the first embodiment. The heat exchanger includes a large number of flat heat transfer tubes 1 in which the refrigerant flows and extends in the lateral direction, a plurality of fins 2 into which a large number of flat heat transfer tubes 1 are inserted, and heat exchange with the refrigerant is performed. The headers 3x and 3y are connected to one of the flat heat transfer tubes 1 and extend in the vertical direction (vertical direction), and the refrigerant is distributed to a large number of flat heat transfer tubes 1. A refrigerant inlet pipe 30 is connected below the header 3x. A refrigerant outlet pipe 33 is connected to the central portion of the header 3x. The refrigerant flows in from the refrigerant inlet pipe 30, flows through the plurality of flat heat transfer pipes 1, and flows out from the refrigerant outlet pipe 33. A partition plate 35x (see FIG. 4) is inserted in the upper part, middle lower part, and lower part of the header 3x. Similarly, partition plates 35x) are inserted into the upper and lower portions of the refrigerant outlet pipe 33 of the header 3y.

FIG. 3 is a diagram showing a configuration of the flat heat transfer tube 1 according to the first embodiment. The flat heat transfer tube 1 includes a heat transfer tube body 11 that forms an appearance, and a partition rib 13 that allows a large number of refrigerant channels 12 to be formed inside the heat transfer tube body 11. The refrigerant that has flowed into the flat heat transfer tube 1 can be uniformly distributed and flown into the multiple refrigerant flow paths 12.

FIG. 4 is a diagram illustrating a configuration of the header 3x of the heat exchanger according to the first embodiment. FIG. 5 is a diagram showing a cross section of the header 3x of the heat exchanger according to the first embodiment. FIG. 5 shows an XX cross section of FIG. The header 3x includes a flat tube side header member 31x (first member) and a combination header member 34x (second member). In addition, partition plates 35x are inserted in the upper, middle, and lower portions of the header 3x.

The narrow flow path 38 is formed by combining the flat tube side header member 31x (first member) and the combined header member 34x (second member).

The flat tube side header member 31x and the combination header member 34x are formed of a plate material, and the flat tube side header member 31x and the combination header member 34x have a D-shaped cross section formed by bending the plate material. A separation portion 39 (see FIG. 7) is provided in a part of the straight portion. The flat tube side header member 31x and the combination header member 34x are combined through the separation portion 39, and the narrow flow path 38 is formed between the D-shaped straight portions of the flat tube side header member 31x and the combination header member 34x facing each other. Forming. In addition, you may manufacture the flat tube side header member 31x and the combination header member 34x, or its combination member by extrusion molding.

FIG. 6 is a diagram showing that the header 3x according to the first embodiment is point-symmetric. The left diagram in FIG. 6 shows a cross section (XX cross section, see FIG. 4) of the header member in which the flat tube header member 31x and the combined header member 34x are combined. When this is rotated 180 degrees around the point O, the right diagram of FIG. 6 is obtained. As shown in FIG. 6, the cross-sectional shape of the header member in which the flat tube side header member 31x and the combined header member 34x are combined is a point-symmetric shape except for the hole position where the flat heat transfer tube 1 is inserted. I understand that.

The flat tube side header member 31x (first member) has an opening 31x3, and the combined header member 34x (second member) has an opening 34x3. The first member and the second member have an opening to which the same heat transfer tube is connected.

The flat tube side header member 31x (first member) has a parallel surface 31x4 parallel to the end surface of the flat heat transfer tube 1, and the combined header member 34x (second member) is parallel to the end surface of the flat heat transfer tube 1. It has a parallel surface 34x4. Each of the first member and the second member has a parallel surface parallel to the end surface of the heat transfer tube, and has at least one bent portion to form the parallel surface. The parallel plane corresponds to the D-shaped straight portion described above.

FIG. 7 is a diagram showing an exploded state of the header of the heat exchanger according to the first embodiment. The combined header member 34x is inserted into the flat tube side header member 31x from the upper part in the vertical direction in accordance with the separation portion 39. Thereafter, the combined header member is inserted into the flat heat transfer tube 1. The partition plate 35x is inserted into the upper part, middle lower part, and lower part of the combined header member.

FIG. 8 is a view showing a longitudinal section of the header of the heat exchanger according to the first embodiment. FIG. 8 shows a YY cross section of FIG. It can be seen that the narrow channel 38 is formed in the header 3x by combining the flat tube side header member 31x (first member) and the combined header member 34x (second member). Accordingly, the speed of the refrigerant inside the header according to the present embodiment is increased as compared with the shape shown as the header cross-sectional structure of the comparative example shown in FIG. As a result, the momentum of the liquid refrigerant increases and the liquid refrigerant can reach the flat heat transfer tube 1 attached to the upper part of the header.

FIG. 9 is a view showing a brazing surface of the refrigerant distributor according to the first embodiment. The clad material is formed by laminating a brazing material 31x1 on the outer side of the base material 31x0 of the flat tube side header member 31x. The clad material is formed by laminating a brazing material 34x1 on the outside of the base material 34x0 of the combination header member 34x. The header structure according to the present embodiment can be brazed with such a configuration using a single-sided clad material.

FIG. 10 is a view showing another brazing surface of the refrigerant distributor according to the first embodiment. FIG. 10 shows the minimum required brazing surfaces 37a, 37b, and 37c. The brazing surface 37a is a joint surface between the flat tube side header member 31x and the flat heat transfer tube 1, and the brazing surfaces 37b and 37c are joint surfaces between the flat tube side header member 31x and the combined header member 34x. In the case of FIG. 10 as well, a substantially narrow channel 38 can be formed.

According to the first embodiment, the narrow flow path 38 can be formed by combining the header members, and by increasing the refrigerant flow rate, the liquid refrigerant can be raised to the upper part of the heat exchanger and the refrigerant distribution can be improved. Moreover, the combination member is a substantially equivalent member and has excellent assemblability.

<< Second Embodiment >>
Example 1
FIG. 11A is a diagram illustrating an external configuration of a heat exchanger according to the second embodiment. FIG. 11B is a diagram illustrating a cross section of the header of Example 1 according to the second embodiment. FIG. 11B shows a cross section taken along line AA in FIG. 11A. As shown in FIG. 11A, there are two headers 3a and 3b arranged substantially vertically on the upstream side and the downstream side, and a plurality of flat heat transfer tubes 1 are connected between them in a substantially vertical direction. In each flat heat transfer tube 1, a plurality of fins 2 that expand the heat transfer area are arranged with a predetermined gap in the horizontal direction. Although the fin 2 is not shown in detail, when the heat exchanger is used as an evaporator, the fin 2 is devised so that water droplets condensed on the fin surface are likely to fall. It also has a shape for defining the gap between adjacent fins to be constant.

The header 3a includes a header base member 31a (first member) which is a concave-shaped member and a header insertion member 34b (second member). Similarly, the header 3b includes a header base member 31b (first member) that is a concave-shaped member, and a header insertion member 34b (second member).

The refrigerant inlet pipe 30 is connected below the header insertion member 34a. In addition, the refrigerant outlet pipe 33 is connected to the header insertion member 34b. The refrigerant flows in from the refrigerant inlet pipe 30, flows through the plurality of flat heat transfer pipes 1, and flows out from the refrigerant outlet pipe 33.

Heat is exchanged between the refrigerant and the air by air flowing between the fins in a direction substantially perpendicular to the paper surface. Under conditions widely used in air conditioners, the air side has a laminar heat transfer coefficient of about several tens to one hundred W / (m ² K), and the flat heat transfer pipe flow path has several thousand W / (m ² K) due to the refrigerant. ) Heat transfer performance with a boiling heat transfer coefficient. Therefore, since the effect of expanding the area on the air side is great, the fins are thin aluminum fins with a fin gap of about 1 mm to several mm so that the area on the air side can be secured as much as possible if the heat exchanger has the same volume. Composed.

The feature of the present embodiment is that the end of the flat heat transfer tube 1 is inserted into a hole provided in the flat portion of the header base member 31a of the concave-shaped member. The header insertion member 34a is inserted into the opposite opening side to which the flat heat transfer tube 1 of the concave shape member is connected. Both of them are brazed in a furnace such as an electric furnace, so that a header structure having a narrow flow path 38 serving as a refrigerant flow path is obtained. Similarly, the header 3b of the other header is inserted into the header base member 31b with the header insertion member 34b to form a narrow channel 38 serving as a coolant channel. That is, the contact surface between the header base member 31a and the header insertion member 34a, which are concave-shaped members, serves as a brazing surface.

In FIG. 11A, the flow of the refrigerant when the heat exchanger is used as an evaporator is indicated by white arrows. In FIG. 11A, the refrigerant that has become low temperature and low pressure due to the action of an expansion valve (not shown) flows through the number of flat heat transfer tubes in parallel for each space partitioned by the partition plates 35a and 35b in the heat exchanger. And a refrigerant | coolant flows upwards through the perforated partition plate 36a (partition plate with a hole), and flows the number of flat heat-transfer tubes in parallel. The refrigerant that has flowed in from the refrigerant inlet pipe 30 flows upward from the lower side of the heat exchanger as the area a → the area b → the area c, and finally flows out from the refrigerant outlet pipe 33.

In addition, although the flow of the refrigerant | coolant which flows upwards simply from the downward direction of a heat exchanger was shown in the figure, the flow which once went downward once for every partitioned space may be included. In this way, when the refrigerant flows from the bottom to the top in the heat exchanger, the supercooled liquid refrigerant accumulates due to gravity when the flow direction is changed by the same heat exchanger and used as a condenser. This is to make it easier to go downward so as not to occur.

In the refrigerant when used as an evaporator, the liquid component gradually evaporates in the flow direction and the gas component increases. Therefore, when flowing with the same flow path cross-sectional area, the pressure loss per unit increases due to the increased flow velocity of the gas refrigerant. As a result, there is a problem that an effective temperature difference with the air cannot be ensured due to a decrease in the saturation temperature of the refrigerant, and the energy saving performance is deteriorated due to an increase in compression work as a whole. Therefore, it is generally performed to increase the number of flat heat transfer tubes that gradually flow in parallel toward the outlet so that the pressure loss does not increase so much.

Fig. 11B shows an enlarged view of the AA cross section. A header insertion member 34a is inserted into the header base member 31a, which is a concave member, and the contact surface is brazed to form a narrow channel 38 (header space). The area inside the header base member 31a of the concave-shaped member defined by a virtual surface on the opening side of the header base member 31a of the concave-shaped member is narrowed by inserting the header insertion member 34a into the narrow-shaped flow. A path 38 is formed. Thus, the speed of the refrigerant inside the header according to the present embodiment is increased as compared with the shape shown as the header cross-sectional structure of the comparative example shown in FIG. As a result, the momentum of the liquid refrigerant increases and the liquid refrigerant can reach the flat heat transfer tube attached to the upper part of the header. Further, there is a perforated partition plate 36a, and the liquid refrigerant is guided upward in a state where the partition plate 36a is narrowed at the smallest area and the flow velocity is increased.

In FIG. 11A, a simplified example of a heat exchanger is shown for the sake of explanation, but actually, a plurality of these basic configurations are stacked in the height direction, or a similar heat exchanger is used for air. A predetermined heat transfer area can be secured by arranging them in the downwind and upwind directions. Furthermore, although the perforated partition plate 36a is provided in one place in FIG. 1 for the sake of simplifying the description, it may be provided in the header 3b at the same height position as the partition plate 35a, which improves the drift in the region b. I can plan.

FIG. 12 is a view of the end of the flat heat transfer tube 1 as viewed from the open side of the header base member 31a of the concave-shaped member (as viewed from the arrow B in FIG. 11A). The flat heat transfer tube 1 is provided with a plurality of small channels of about 1 mm to several mm through which a plurality of refrigerants flow, and is formed by extrusion or drawing. The header base member 31a of the concave shape member and each flat heat transfer tube 1 are brazed at the connection surface 131.

(Example 2)
FIG. 13A is a diagram illustrating a cross section of the header of the heat exchanger of Example 2 according to the second embodiment, and the header insertion member 34a is a diagram of a concave shape member. FIG. 13B is a diagram showing a cross section of the header of the heat exchanger of Example 2 according to the second embodiment, and the header insertion member 34a is a cylindrical shape (hollow shape). FIG. 13C is a diagram illustrating a cross-section of the header of the heat exchanger of Example 2 according to the second embodiment, and the header insertion member 34a is an H-shaped diagram. FIG. 13D is a diagram illustrating a header cross section of the heat exchanger of Example 2 according to the second embodiment, and the header insertion member 34a is a trapezoidal shape.

FIG. 13A is a reference configuration, and similarly to the header base member 31a of the concave-shaped member, the header insertion member 34a is also configured of a concave-shaped member that opens in the same direction. Such a configuration can most reduce the weight of the header portion as long as the strength with the header internal pressure is secured.

FIG. 13B shows the header insertion member 34a having a cylindrical shape (hollow shape). In such a configuration, it is possible to increase the rigidity of the header insertion member 34a. The header insertion member 34a may be a solid material. In this case, the rigidity can be further increased.

FIG. 13C shows that the header insertion member 34a is formed of a substantially H-shaped member. It can be manufactured by extrusion processing, and it becomes possible to further narrow the flow path area surrounded by the concave header base member 31a.

FIG. 13D shows the header base member 31a, which is a concave-shaped member, having a laterally widening cross section. With such a configuration, it is possible to perform brazing while applying a contact load to the contact surface by fixing using a jig or the like of the header base member 31a and the insertion member 34a of a concave-shaped member, or brazing while binding.

In addition, although each figure has shown as the shape which aligned the opening side end surface of the header base member 31a of a concave shape member, and the surface of the header insertion member 34, the shape which provided the level | step difference may be sufficient. When the end faces are aligned, the assembly accuracy of the parts can be improved, and the assembly condition can be managed by confirming the appearance.

(Example 3)
FIG. 14: is a figure which shows the cross section of the header of the heat exchanger of Example 3 which concerns on 2nd Embodiment. The difference from the invention up to FIG. 13 is that the other end is longer like 31a1 as compared to the end length of the header base member 31a of the concave-shaped member. With such a configuration, since the heat exchanger can be fixed via the housing 319 and the joining component 318, a separate member for fixing becomes unnecessary. Note that it is not necessary to provide all the stretched 31a1 in the longitudinal direction, and the material and weight can be reduced by providing only the portions necessary for fixation. Although FIG. 14 shows an example in which the heat exchanger and the casing are fixed, they may be used for fixing the heat exchangers.

Example 4
FIG. 15: is a figure which shows the cross section of the header of the heat exchanger of Example 4 which concerns on 2nd Embodiment. The clad material is formed by laminating a brazing material shown as 31a2 on the outer side of the base material 31a0 of the header base member 31a of a substantially U-shaped member. Further, the brazing material 34a1 is applied to the outside of the base material 34a0 of the header insertion member 34a. The header structure according to the present invention can be brazed with such a configuration using a single-sided clad material.

(Example 5)
FIG. 16A is a diagram illustrating a header cross-section of the heat exchanger of Example 5 according to the second embodiment, and serves as a reference. FIG. 16B is a diagram illustrating a header cross section of the heat exchanger of Example 5 according to the second embodiment, and is a diagram in which the insertion length of the header insertion member 34a is set longer. FIG. 16C is a diagram illustrating a header cross section of the heat exchanger of Example 5 according to the second embodiment, and is a diagram in which a member 340 different from the header insertion member 34a is inserted into the flow path.

FIG. 16B sets the insertion length of the header insertion member 34a inserted into the header base member 31a, which is a concave-shaped member, to be longer than that of FIG. 16A. By making the insertion length longer, it becomes possible to make adjustments such as reducing the flow path area of the refrigerant. In FIG. 16C, a member 340 different from the header insertion member 34a is inserted into the flow path cross section. With such a configuration, the refrigerant flow path can be further narrowed, so that the flow path can be partially narrowed in accordance with the region in the heat exchanger, and the degree of freedom in adjusting refrigerant drift in advance is increased. In FIG. 16B, it is preferable that the gap D between the outer surface of the insertion member 34a and the end surface of the flat heat transfer tube 1 inserted in the header facing the outer surface is 1 mm to 3 mm.

(Example 6)
FIG. 17A is a diagram illustrating a method of attaching the perforated partition plate 36a (partition plate with holes) in the header of Example 6 according to the second embodiment. FIG. 17B is a diagram showing another example of a method for attaching the perforated partition plate 36a in the header of Example 6 according to the second embodiment. FIG. 17C is a diagram illustrating another example of the attachment method of the perforated partition plate 36a in the header of Example 6 according to the second embodiment. The perforated partition plate 36 a has a square hole 360.

In FIG. 17A, the perforated partition plate 36a is installed by inserting the projection 36a1 of the perforated partition plate 36a into the hole 34a2 of the header insertion member 34a, and is built into the opening of the header base member 31a and brazed. FIG. 17B shows that the leakage of the refrigerant can be reduced by cutting off the corners of the insertion member 34a as shown in the drawing or by processing it into a round shape. In FIG. 17C, a groove 34a3 is provided in advance in the header insertion member 34a, and a perforated partition plate 36a having a protrusion 36a1 is provided in the groove 34a3.
Although FIG. 17 shows an example of the perforated partition plate 36a, the fixing method shown in FIG. 17 may be applied to the partition plates 35a and 35b.

(Example 7)
FIG. 18A is a diagram illustrating a configuration of the perforated partition plate 36a of the header of Example 7 according to the second embodiment. FIG. 18B is a diagram showing another configuration of the header perforated partition plate 36a of Example 7 according to the second embodiment. 18A and 18B relate to the perforated partition plate 36a described in the sixth embodiment. FIG. 18A shows a configuration in which one hole 360a is formed. FIG. 18B shows a configuration in which two holes 360a are formed. A round hole as well as the square hole shown in FIG. 17 may be used, and a faster refrigerant speed can be realized in the header space by selecting the hole diameter.

(Example 8)
FIG. 19A is a diagram illustrating a perforated plate 132 for preventing drift in the header 3a of Example 8 according to the second embodiment. FIG. 19A is a view showing a CC cross section of FIG. FIG. 19B is a perspective view of the perforated plate 132 for preventing drift in the header 3a of Example 8 according to the second embodiment. A perforated plate 132 is built in the header base member 31a, which is a concave member, so that the end face and the surface of the flat heat transfer tube 1 are aligned. The perforated plate 132 is provided with a plurality of holes 133 into which the flat heat transfer tubes 1 are inserted. With such a configuration, the gap between the side surface of the flat heat transfer tube and the step between the upper and lower sides can be filled, so that the step in the flow path can be reduced and the drift due to the disturbance of the refrigerant in the header can be prevented.

Example 9
FIG. 20 is a diagram illustrating the position of the partition plate of the header insertion member of Example 9 according to the second embodiment. As shown in FIG. 1, the header 3a is configured to insert a header insertion member 34a into a header base member 31a. In (b-1), (b-2), and (b-3) of FIG. 20, the mounting height positions of the partition plate 35a and the perforated partition plate 36a with respect to the header insertion member 34a are changed. Thus, while the header base member 31a of the concave-shaped member is used in common, the refrigerant described above can be changed by changing the mounting position of the header insertion member 34a and the partition plate (for example, the partition plate 35a and the perforated partition plate 36a). The combination of the number of flat heat transfer tubes to flow can be set freely. As a result, it is possible to make adjustments at the design stage, such as differences in capability models and whether to prioritize the performance of the condenser or the evaporator.

According to the second embodiment, the refrigerant distribution to the flat heat transfer tubes of the parallel flow type heat exchanger can be made uniform, and the heat exchanger can be operated efficiently. Thereby, the energy-saving property of an air conditioner can be improved.

According to this embodiment, even during operation under a minimum load condition or an intermediate load condition, it is possible to suppress a deviation in the amount of liquid refrigerant supplied to each flat heat transfer tube in the parallel flow evaporator with a simple structure. Headers 3a, 3b, 3x, 3y can be provided. Therefore, it is possible to realize a heat exchanger having a header (indoor heat exchanger 101, outdoor heat exchanger 106) (see FIG. 21), an air conditioner AC (see FIG. 21) including the heat exchanger, and an air conditioning system.

Note that the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding by the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.

DESCRIPTION OF SYMBOLS 1 Flat heat exchanger tube 2 Fin 3a, 3b, 3x, 3y Header (refrigerant distributor)
8 Compressor 9 Four-way valve 30 Refrigerant inlet pipe 33 Refrigerant outlet pipe 31a, 31b Header base member (first member)
31x Flat tube side header member (first member)
34a, 34b Header insertion member (second member)
34x combination header member (second member)
35a, 35b, 35x Partition plate 36a Perforated partition plate (partition plate with holes)
38 Narrow channel 39 Separation part (separation part)
90 Two-phase area 91 Superheated area 100 Indoor unit 101 Indoor heat exchanger 102 Indoor fan 103 Expansion valve 105 Outdoor unit 106 Outdoor heat exchanger 107 Outdoor fan 131 Connection surface 132 Perforated plate 133 Hole 318 Mounting bracket 319 Housing 360, 360a hole AC air conditioner

Claims (18)

1. Refrigerant distributors that connect to ends of a plurality of heat transfer tubes that form a refrigerant flow path, communicate the plurality of heat transfer tubes, and distribute the refrigerant,
   The refrigerant distributor includes a first member and a second member combined with each other,
   A refrigerant distributor that forms a narrow flow path by combining the first member and the second member.
2. The first member and the second member are formed of a plate material,
   The first member and the second member have a D-shaped cross-sectional shape formed by bending the plate material, and have a separation portion in a part of the D-shaped linear portion,
   The first member and the second member are combined through the spacing portion,
   2. The refrigerant distributor according to claim 1, wherein a narrow channel is formed between the D-shaped linear portions of the first member and the second member facing each other.
3. The refrigerant distributor according to claim 1, wherein a cross-sectional shape of a member obtained by combining the first member and the second member is a point-symmetric shape.
4. The refrigerant distributor according to claim 1, wherein the first member and the second member have an opening to which the same heat transfer tube is connected.
5. The first member and the second member each have a parallel surface parallel to the end surface of the heat transfer tube,
   The refrigerant distributor according to claim 1, further comprising at least one bent portion for forming the parallel surface.
6. The refrigerant distributor according to claim 2, wherein a brazing material for bonding is applied to one side of the first member and the second member.
7. The first member has a concave cross section,
   The refrigerant distributor according to claim 1, wherein the second member is fitted to an inner surface of the first member to form the narrow channel.
8. The refrigerant distributor according to claim 7, wherein the cross-sectional shape of the second member is any one of a concave shape, a cylindrical shape, a solid shape, an H shape, and a trapezoid shape.
9. The refrigerant distributor according to claim 7, wherein one end of the open end of the concave member of the first member extends beyond the other end.
10. The refrigerant distributor according to claim 7, wherein brazing materials are stacked on the outer side of the concave member that is the first member and on the outer side of each base material of the second member.
11. The refrigerant distributor according to claim 7, wherein the second member has a different insertion length in the first member.
12. The refrigerant distributor according to claim 7, wherein a partition plate with a hole having a hole can be fixed to the second member.
13. The refrigerant distributor according to claim 12, wherein the partition plate with holes has at least one square hole or round hole.
14. The refrigerant distributor according to claim 7, wherein a member capable of narrowing a flow path space is provided inside the concave member of the first member.
15. A large number of refrigerant pipes flowing in the transverse direction and flowing through the refrigerant;
    A plurality of refrigerant pipes inserted therein, heat radiating fins for heat exchange between the refrigerant and the fluid; and
    A refrigerant distributor coupled to one of the plurality of refrigerant pipes and extending in a longitudinal direction so that the refrigerant is distributed to the plurality of refrigerant pipes;
    The heat exchanger that is the refrigerant distributor according to any one of claims 1 to 14, wherein the refrigerant distributor is a refrigerant distributor.
16. A heat exchanger comprising two refrigerant distributors, a plurality of heat transfer tubes connecting the two refrigerant distributors, and a fin for expanding the heat transfer area of the heat transfer tubes,
    Refrigerant flows from the bottom of one space region in the refrigerant distributor,
    The refrigerant distributor is a heat exchanger in which a second member, which is an insertion member, is fitted to the inner surface of a first member having a concave cross section connected to a heat transfer tube to form a narrow channel.
17. The heat exchanger according to claim 16, wherein a gap between an outer surface of the second member and an end surface of the heat transfer tube inserted into the refrigerant distributor facing the outer surface is 1 mm to 3 mm.
18. An air conditioner comprising the heat exchanger according to claim 15.

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